Suchergebnisse

Разработана концепция запуска военно-транспортного самолета АН 70 с минимальными потерями мощности. Предложена оптимальная по быстродействию система частотно-токового управления асинхронным двигателем привода винта самолета на основе автономного инвертора напряжения с широтноимпульсной модуляцией по закону синуса. Для контроля температуры корпуса двигателя в режиме запуска один из контуров системы выполнен на основе фаззи-регулятора. ; Розроблено концепцію запуску військово-транспортного літака АН 70 з мінімальними втратами потужності. Запропоновано оптимальну за швидкодією систему частотно-струмового керування асинхронним двигуном приводу гвинта літака на основі автономного інвертора напруги з широтно-імпульсною модуляцією за законом синусу. Для контролю температури корпусу двигуна в режимі запуску один з контурів системи виконано на основі фаззі-регулятора. ; The concept of the engine start in military transport aircraft AN-70 with minimal power losses has been developed. The construction of the frequency control system optimal by fast speed for asynchronous motor current of the aircraft propeller drive has been proposed. It was performed based on the stand-alone voltage inverter with sinusoidal pulse-width modulation. One of the system loops is built based on fuzzy regulator to control the temperature of the motor case within the starting mode.

Electrification policies are crucial to improve the welfare of rural populationsworldwide. In this context, auctions for the deployment of stand-alone solar home systems (SASHS) are an appropriate alternative to facilitate access to electricity in rural areas. The aim of this paper is to analyze the design elements and functioning of the SASHS auction in Peru in order to derive lessons for the effective and efficient design of those auctions. Based on an analytical framework developed elsewhere, this article draws on official documents and data, secondary material and interviews with stakeholders. Our results show that some design elements are particularly suitable in this regard. In contrast to renewable electricity auctions in general, for which the volume auctioned is usually set as capacity (MW) or generation (MWh), the volume of SASHS auctions should be set in terms of the number of SASHS providing an electricity service.Geographical diversity,with different auctions per region, would ensure the adoption of a minimum amount of SASHS in a given geographical area. Financial solvency, but not technical reputation, should be required. Otherwise, only the incumbents would be able to participate in the auction. The choice of technology-specific, price-only, sealed-bid, single-item auctions brings benefits in terms of economies of scale, lower support or transaction costs and a greater transparency or simplicity. A correction factor on the remuneration which accounts for the quality of the service, as applied in the Peru auction, is suitable for this type of auctions. Finally, provision of technical information, which facilitates the participation in the auction, and the implementation of a non-disclosed ceiling price are deemed appropriate. In contrast, given the lowpresence of local companies in the Peruvian PV market, the adoption of local content requirements would lead to higher support costs without significantly increasing the local development potential. ; The authors would like to acknowledge Mr. Julio Eisman Valdés forhis guidance and support and Mr. Mats Marquardt (Factor) for editingsupport. Dr. Cabeza would like to thank the Catalan Government forthe quality accreditation given to her research group GREiA (2017 SGR1537). GREiA is certified agent TECNIO in the category of technology de-velopers from the Government of Catalonia. This work is partially sup-ported by ICREA under the ICREA Academia program

Recently, the environmental objectives set by the European Union to reduce CO2 emissions and to increase the renewable share, together with the reduction of PV prices since 2010, have motivated a great interest in PV heat pump systems for heating and cooling applications. This papers describes the initial characterization test and results of a stand-alone PV heat pump prototype installed in Madrid (Spain), using a water tank as thermal storage instead of batteries as electricity storage (a more expensive and technically complex solution). This initial test has the objective of characterizing the response of the converter that operates the compressor of the heat pump. Such converter was powered by a constant frequency input (the electric grid), in order to quantify the variable frequency output that the compressor demands. In future work, the converter will be powered by a PV array (which means a variable frequency input) and programmed to provide the required output without overcoming any limit value of the system. This way, the heat pump system will be operated completely stand-alone.

Since the early 1990's the number of corporate stand-alone reports produced by various organisations worldwide has increased considerably (Kolk, 2004; Owen, 2006). It is argued that introducing an assurance statement with the stand-alone report may contribute to enhancing the credibility of the reported information (FEE, 2002; Dando and Swift, 2003; ACCA and AccountAbility, 2004). This thesis reports on a multi-level analysis of assurance statements attached to stand-alone reports that were produced by the UK FTSE100 companies during the reporting years 2000-2004. Drawing on a research instrument (which itself has been informed by previous literature, namely O'Dwyer and Owen, 2005) as well as the most recent assurance guidelines and standards (such as FEE, 2002; GRI, 2002, AA1000AS, 2003; and ISAE3000, 2004), this thesis examines the extent to which assurance statements disclose information about crucial elements of the assurance engagement, the amount of disclosure as well as factors associated with the information disclosed. In this context, particular attention is given to issues of independence of the assurance provider; the methodology used to conduct the assurance engagement; the degree to which stakeholders have been engaged and their issues taken account of within the assurance process; and assurance results (namely presentation of the assurance opinion, findings and recommendations). The research results suggest that, despite the increased amount and quality of information disclosed within the assurance statements over the years, engagement of stakeholders and taking adequate account of their issues within the assurance process is still lacking compared to other dimensions of assurance. In the absence of generally accepted stand-alone reporting criteria and assurance standards for this type of reporting, various assurance approaches have emerged and these correspond to the nature of the assurance provider (for example, accountancy, consultancy and certification body). The FTSE100 companies (in almost in two-thirds of the conducted engagements) rely most heavily on consultancy firms for assurance and as a result, this approach dominates UK assurance practice. As a consequence, there are noticeable variations in the assurance methodologies, results of the assurance engagements (findings, opinions and recommendations) and shape of the assurance statements over the study. There are also changes that emerge over time and these are most strongly associated with the standards that are used to govern the assurance engagement and also the type of information being assured. These findings raise concerns about whether it is possible to harmonise assurance practice of the corporate stand-alone reports. This thesis concludes with some practical implications for the assurance of stand-alone reports, as well as recommendations for future research.

Based on video recordings of everyday German face-to-face interaction, we focus on how eyebrow furrows, eyebrow raising, eye widening, and freeze-look are used without co-occurring verbal repair initiations to indicate a problem in another participant's turn. Unlike verbal initiations, facial other-initiations of repair only minimally disrupt the progressivity of interaction, since they can be used simultaneously with the emerging trouble-source turn and do not initiate a side sequence. Through their early positioning and their sequentially unobstructive character, facial other-initiations of repair systematically provide an occasion for the speaker of the repairable turn to carry out self-repair at the next transition-relevance place. Our findings point to the necessity of reconsidering traditional conceptualizations of the repair system in order to take bodily repair-initiating practices into account.